Epitaxy is a process that is used extensively in semiconductor processing to form very thin material layers on semiconductor substrates. These layers frequently define some of the smallest features of a semiconductor device, and they may have a high quality crystal structure if the electrical properties of crystalline materials are desired. A deposition precursor is normally provided to a processing chamber in which a substrate is disposed, the substrate is heated to a temperature that favors growth of a material layer having desired properties.
Epitaxy processes are typically performed in a reactor by disposing a substrate in the reactor, flowing a precursor gas mixture into the reactor, and performing a reaction that deposits a film on the substrate. Unreacted gases, byproducts, and any gases released by the substrate flow out of the reactor to an exhaust handling system. These gases are typically not recovered.
As manufacturing standards increase, efforts continue to make manufacturing processes more efficient and cost effective. There remains a continuing need for low-cost semiconductor processing chambers and processes.